Elastic-fluid turbine.



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terrors a. sonnntnnaor onrrron nrncrnrceonran'v, a co la iMASSACHUSETTS, ASSIGNOR 'TU GENERT RIIPOMt'JlJEUN OlE NEW YRK.`

ELASTJIC-IFLUID TURJBIINJE.

v Specification of Letters Patent.

patented api. as, raie.

.application nled September 25, 1917. Serial No. 193.20%. l

- bucket heights .in the last stages become very high relative to thepitchdiameter of the wheels due to the high'specilic power met with linsuch stages. 'lhe ed'ect of this is iirst to make the spacing ont the-bucketslarge at their outer endsand small at their roots,

and second to make the linear velocity of the buckets much greater attheir outer ends till - impulse blad than at their roots. rll`he eilectvof this is to decrease the efficiency of such wheels, since for anyparticular elastic duid pressure and velocity there is a correspondingbucket spacing and wheelvelocity which gives the highest efficiency. lt,therefore, the buckets are correctly spaced and have the desiredvelocity at their central portions, for example, then lthey are tooclose together and `do not have suilicient velocity at their roots andare spaced too farapart and have too great a velocity at their outerends. f

The object of the `present inventioii is to'- `remedy these defectsto agreat entent and t0 provide a bucket wheel and` turbine struc' turewhiehwill give a. better ediciene than heretofore. 'lo this end lprovide a bucket wheel having two or more concentric rings or blades,the outer ring or rings being reaction buckets or blades and the innerring or rings being reaction buckets or blades having a lesser degree ofreaction than the or even being impulse buckets or blades. lnthisconnection it is pointed out that it is well-known that a re. actionblading may be constructed with various degrees ot reaction in themoving guides or blade rings. The gr sure dropl in such moving guides orrings and the greater the necessary peripheral speed for a givenpressure drop through the stationary and movin guideeor blade rings. asthis reaction in thefjmogblade i. y approaches aero, such blade approaes., ln other wo s the i lcome since theblading ent instance theindicates the tor the blade rings shown. llt has a set of eater the`amount of reactiomthe greater 1s the presof blades may be spacedseparately; and the.

second ditiiculty is to a great extent overdegree oi speed, which aspointed out sired arrangement.

ln the drawing which illustrates my invention, Figure part of a turbinerotor and the adjacent cooperating stationary member; Fig. 2 is a sideelevation of a portion of a ring oit blading, and Fig. 3 is a top planview ot liig. 2 with the outer bucket cover omitted. :terring to thedrawing 5 indicates a turbine rotor, here shown in the form of a wheel.0n its periphery is mounted a blading comprising two concentric' ringsor blades, the inner one 6 being bladinghaving one bein blading having aeater de ee of reacteion. ln the first insnce` the lrading may have zeroreaction and hence the impulse blading. They may be joined together inany suitable manner. ln the presblades 6 are fastened in a slot 8 'inthe rim of the rotor in a wellknown manner, and they are provided withafcover 9 in which is cut a slot 10 for the reception of the bases ofthe ring of, blades 7. The ring of blades 7 may be provided with a suitale cover, as indicated at 11. 12 coperating stationary member above isthe dedlrectingvanes or nozzles 13 for thering of blades 7, and a secondset 1t for the ring of blades 6.. They are separated by a suitablepartition 15 in line with the blade cover 9. Between adjacent stationaryand moving parts, as between members l1 and 12,- there is a very smallclearance to prevent leakage as mitch as possible. 'lhismay be an axialclearance as shown ora radial Y having the greatestl reaction w1ll havethe greatest` l is a sectional view of a degree of reaction and theouter one 7,

uti-

iva-f ;g.fone, whichever suits the picular. term et ,.eonstruction best;also close clearances or suitable pac lized at other points to preventleakage as found desirable.

The two rings of blading 6 and 7 are separately assembled, and, as -isclear from an inspection of Figs. 2 and 3, the blades 6 are spaced inthe most advantageousmanner as are also the blades 7. It will also beclear that the blading" 7 willhave a 'greater peripheral speed than theblading 6 which is the desired' arrangement, 'as already eX- plained. i

In accordance withy the provisions of the patent statutes, Ihavedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodimentthereof;but I desire to have it understood that the apparatus shown isonly illustrative, and' that the invention can be carried out by othermeans. y

What I claim 'as new and desire to secure by Letters Patent of theUnited States, is-

1. Aturbine rotor having a blading thereon comprising two concentricblade rings the radially inner one having a lesser degree of reactionthan the outer one.v

2. A turbine rotor having a blading thereon comprising two concentricblade rings, the radiallyinner one being made up 0f impulse blades, andthe radially outer one of reaction blades.

3. In an elastic fluid turbine, the combination of a rotor, a ring of imulse blading thereon, a cover for such bladlng, a -ring of reactionblading carried by said cover, and means for supplying elastic luid tolsaid rings of bladings.

y 4. In an elastic fluid turbine, the combinavtion of a rotor, a ring ofreaction blading thereon, a cover for such blading, a ring of reactionblading carried by said cover having a higher degree of reaction thanthe first ring, and means for supplyingA elastic uid to said rings ofbladings..

In witness whereof, I have hereunto set my hand this 17th day ofSeptember, 1917.

CHRISTOPHER A. soHELLENs.

